Brännmark, who competes for the Piteå Elit SK , has mainly participated in FIS races since 2008 and ran his first race in the Scandinavian Cup in Åsarna in January 2012 , finishing 99th in the sprint. He made his World Cup debut in February 2016 in Falun . He achieved 71st place in the 15 km mass start race and 66th place over 10 km classic. In the 2019/20 season he scored his first World Cup points in Lahti with 27th place over 15 km classic and at Holmenkollen with 24th place in the 50 km mass start race.